Tag: atmosphere

The nuclear disaster at the Fukushima Daiichi power plant this spring may have released twice as much radiation into the atmosphere as the Japanese government estimated, a new preliminary study says. While the government estimates relied mostly on data from monitoring stations in Japan, the European research team behind the new report looked at radioactivity data from stations scattered across the globe. This wider approach factored in the large amounts of radioactivity that were carried out over the Pacific Ocean, which the official tallies didn’t.

What’s the News: An international team of researchers, led by the National Center for Atmospheric Research, has learned that large magnetic waves are partly to blame for the Sun’s immensely hot corona. The study, published in the journal Nature, also suggests that the waves could be the driving force behind the solar wind.

In this images of infrared radiation in the days before the March 11 earthquake, the red circle indicates the epicenter and the red lines are tectonic faults.

What’s the News: Scientists analyzing the March 11 earthquake in Japan will have the benefit of some of the most sensitive and comprehensive atmospheric data yet, thanks to satellites monitoring climate. And a team has now reported a strange effect—a sudden spike in the temperature in the atmosphere above the quake site—detected just before the event. If the spike was related to the quake, and other earthquakes do the same thing, it might help scientists predict such cataclysms in the future.

Last year, astronomers discovered a remarkable planet orbiting another star: it has a mass and radius that puts it in the “super-Earth” category — meaning it’s more like the Earth than a giant Jupiter-like planet. Today, it has been announced that astronomers have been able to analyze the atmosphere of the planet (the very first time this has ever been accomplished for a super-Earth), and what they found is astonishing: the air of the planet is either shrouded in thick haze, or it’s loaded with water vapor… in other words, steam!

…

Astronomers observed the planet when it passed in front of the star, analyzing the light very carefully. As starlight passes through the planet’s atmosphere, certain colors of it get absorbed, and these are like fingerprints that can be used to figure out the atmospheric composition. Most models predicted a heavy hydrogen content, but the observations indicate none is there! That means either there are thick layers of haze in the upper atmosphere of the planet, obscuring any hydrogen below them — much like Venus or Saturn’s moon Titan, blocking the view lower down — or there is a vast amount of water in the planet’s air. And at a temperature of 200° C, that water would be in the form of vapor. In other words, steam.

When the news comes from Saturn’s moons, the source is typically Titan—with its hazy atmosphere and frigid surface lakes of methane—or Enceladus—with its plumes of water ice. Last week, however, word came that Rhea, the second-largest Saturnian satellite, has some surprises of its own.

In Friday’s edition of Science, a study by Ben Teolis and colleagues confirmed that during a pass of the moon in March, when the ever-reliable Cassini spacecraft cruised over Rhea’s pole at an altitude of just 60 miles, it directly sampled tiny amounts of oxygen and carbon dioxide there.

“This really is the first time that we’ve seen oxygen directly in the atmosphere of another world,” said Andrew Coates, at UCL’s Mullard Space Science Laboratory, a co-author of the study. [The Guardian]

It’s just a lab experiment, but University of Arizona researcher Sarah Horst says that her team’s re-creation of the atmosphere on Saturn’s moon Titan showed that atmospheric reactions could produce some of life’s basic ingredients, and do it without the presence of liquid water.

Titan, which is larger than Mercury, boasts a thick atmosphere of mostly nitrogen with dashes of methane, carbon monoxide, and other trace ingredients (At -290 degrees Fahrenheit, Titan is a tad too frigid for liquid water). Horst brewed up an approximation of that mixture. She and her colleagues then blasted it with radio-frequency radiation, a lab stand-in for ultraviolet radiation from the sun.

NASA’s next rendezvous with the Red Planet got the go-ahead this week. The space agency approved development of MAVEN, the Mars Atmosphere and Volatile Evolution mission, which is scheduled to launch in November 2013.

In the last decade, missions like the Phoenix Lander, the Spirit and Opportunity rovers, and the Mars Express have reinforced the case that our neighbor was once watery, and far more hospitable to life than the planet we see today. The ancient evidence of liquid water suggests that the planet once had a dense atmosphere, which is now long gone. MAVEN’s mission is to investigate the interaction between Mars’s now-thin atmosphere and the solar wind, and to look for clues to how and when the sun stripped away the planet’s thick atmosphere.

Many researchers think that Mars’s loss of its magnetic field billions of years ago started the process.

“Mars can’t protect itself from the solar wind because it no longer has a shield, the planet’s global magnetic field is dead,” said [lead investigator Bruce] Jakosky, describing how the magnetic field disappeared and the atmosphere then exposed to the punishing solar wind. [AFP]

For more details about MAVEN, check out our coverage from 2008, when NASA first announced the mission. The team’s critical design review will come next July, which could be the true make-or-break time for the mission.

Schemes to hack the planet and save us from global warming have two layers of obstacles to overcome. First, is it technologically and physically possible to do what’s proposed? And then there’s the second: Is it politically possible to tinker with the planet?

Those who would argue “absolutely not” to the latter got a boost by a new study out in Nature Geoscience. Katharine Ricke and her team modeled the effects of one of the most popular geoengineering plans: seeding the atmosphere with aerosols to reflect away some of the sun’s rays, mimicking the way a massive volcanic eruption can cool the Earth. Ricke found that the effects on rainfall and temperature could vary wildly by region—and that what’s best for one country could spell disaster for another.

For example, Ricke says, her study found that levels of sulphate that kept China closest to its baseline climate were so high that they made India cold and wet. Those that were best for India caused China to overheat. She notes, however, that both countries fared better either way than under a no-geoengineering policy [Nature].

You can’t rise from the primordial ooze if that ooze is frozen. But about three billion years ago the sun was around thirty percent dimmer, meaning our planet should have been a snowball. The puzzle has haunted scientists for decades, but a study in Science has a new answer: It argues that a dense cloud of “fractal haze” enveloped the Earth.

Old Theories

This isn’t the first attempt to solve the early Earth conundrum. Carl Sagan, for one, had a few ideas. First, in 1972, he speculated that the atmosphere had ammonia which could trap heat, but later work showed that the sun’s ultraviolet radiation would have broken that ammonia down. In 1996 he tried again, saying that Earth might have had a thick haze, perhaps a nitrogen-methane mix, that blocked the ultraviolet but let in enough of the sun’s then-meager rays to warm the planet. Unfortunately, that too was a no go:

Early models assumed the haze particles were spheres, and that when individual particles collided, they globbed together to make bigger spheres. These spheres blocked visible light as well as ultraviolet light, and left the Earth’s surface even colder. “It basically led us to a dead end where we couldn’t have a warm early Earth,” said Eric Wolf, a graduate student in atmospheric sciences at the University of Colorado at Boulder and the first author of the new study. [Wired]

Twenty-five years ago this month, British scientists announced their discovery of the ozone hole over Antarctica. That bolt from the blue spurred perhaps the best-coordinated international response to an environmental crisis to date. Now, scientists can’t help but wonder: Why didn’t the same thing happen with climate change?

Looking back on the ozone problem: Even before the discovery of the hole in the ozone layer—that blanket of three-oxygen “ozone” molecules that protect us from much of the sun’s ultraviolet radiation—researchers worried about pollutants destroying those highly reactive molecules. The British scientists’ 1985 announcement confirmed that daunting reality.

Technically a substantial thinning of the ozone layer, the ozone “hole” has been opening every spring since the 1970s, the scientists reported. Their data, collected at the Halley Research Station in Antarctica, suggested that CFCs were to blame. That’s because atmospheric conditions during the cold, dark, Antarctic winters were building stockpiles of CFCs over the South Pole [National Geographic].